TC32钛合金超高周疲劳性能研究

Study on ultra-high cycle fatigue performance of TC32 titanium alloy

应用20kHz超声疲劳试验系统和高频疲劳试验系统,对TC32钛合金材料室温对称载荷作用下的超高周疲劳进行了研究。结果表明:疲劳循环在10~7周次后仍会发生断裂,不存在明显的疲劳极限,S-N曲线呈现双线性特征;从疲劳断口特征来看,较高应力下为表面萌生机制,而在低应力超高周疲劳范围内,裂纹则主要于亚表面萌生;加载频率对TC32钛合金疲劳行为无明显影响。

The ultra-high cycle fatigue performance and failure mechanism of TC32 titanium alloy under the action of room temperature and symmetric load were studied by 20 kHz ultrasonic fatigue test system. The result shows that break will still arise after 10~7 cycles, there is no obvious fatigue limit, the SN curve exhibits bilinear characteristics;At higher stress, the surface initiation mechanism is exhibited, while in the low stress and high cycle fatigue range, the crack is mainly caused at subsurface;the loading frequency has no significant effect on the fatigue behavior of TC32 alloy.